Ultra light tackle. Small J or aberdeen hooks, and night crawlers. Corn will work sometimes also.
Myself and TA2D can easily catch a couple dozen in the creeks we know hold them in Nemaha County.
As a side note...if you start catching bullheads big or small, i would find a different area in the creek or a different creek all together. That is unless you want some bullheads.
Let me know if you need some. Depending on where you're located, myself and TA2D end up selling a decent amount to bait shops, and boy do the bait shops make a profit.
SudDawg